Thread: Unable to encrypt using AES 256bits

Hi,

i trying to write a method to encrypt data using AES 256 but everytimes when i trying to pass the 256bits key to the java cipher it throw Invalid Key Exception, it works only for 128bits key. Below is part of my code

KeyGenerator keygen = KeyGenerator.getInstance("AES");
keygen.init(256);
SecretKey secret = keygen.generateKey();
System.out.println(secret.getEncoded().length);
SecretKeySpec spec = new SecretKeySpec(secret.getEncoded(),"AES");
 
Cipher cipher = Cipher.getInstance("AES");
cipher.init(Cipher.ENCRYPT_MODE, spec);

It show that the key is 32 bytes which is 256bits but when i put the key into cipher.init() it throw invalid key error. I think it is the transformation "AES" which i pass to cipher.getinstance() is wrong. Anyone know what is the correct transformation for 256bits AES encryption?

Thanks.

Hi,

The problem is resolved. To use AES 256bits, you need to download the unlimited strength JCE policy files from Sun and install it. Replace the 2 jar files in your jdk folder.

https://cds.sun.com/is-bin/INTERSHOP...-CDS_Developer